PyCharm 2017.2 Help

Compiling Stylus to CSS

This feature is supported in the Professional edition only.

Introduction

Stylus code is not processed by browsers that work with CSS code. Therefore to be executed, Stylus code has to be translated into CSS. This operation is referred to as compilation and the tools that perform it are called compilers.

PyCharm supports integration with a compiler tool that translates Stylus code into CSS.

In PyCharm, compiler configurations are called File Watchers. For each supported compiler, PyCharm provides a predefined File Watcher template. Predefined File Watcher templates are available at the PyCharm level. To run a compiler against your project files, you need to create a project-specific File Watcher based on the relevant template, at least, specify the path to the compiler to use on your machine.

In either installation mode, make sure that the parent folder of the Stylus compiler is added to the PATH variable. This enables you to launch the compiler from any folder.

PyCharm provides user interface both for global and project installation as well as supports installation through the command line.

Before you start

Download and install Node.js. The runtime environment is required for two reasons:

The Stylus compiler is started through Node.js.

NPM, which is a part of the runtime environment, is also the easiest way to download the Stylus compiler.

If you are going to use the command line mode, make sure the path to the parent folder of the Node.js executable file and the path to the npm folder are added to the PATH variable. This enables you to launch the Stylus compiler and npm from any folder.

Installing the Stylus compiler globally

Global installation makes a compiler available at the PyCharm level so it can be used in any PyCharm project. Moreover, during installation the parent folder of the compiler is automatically added to the PATH variable, which enables you to launch the compiler from any folder.

Run the installation from the command line in the global mode:

Open the embedded Terminal (View | Tool Windows | Terminal) and switch to the directory where NPM is stored or define a PATH variable for it so it is available from any folder, see Installing NodeJs.

Type the following command at the command prompt:

npm install -g stylus

The -g key makes the compiler run in the global mode. Because the installation is performed through NPM, the Stylus compiler is installed in the npm folder. Make sure this parent folder is added to the PATH variable. This enables you to launch the compiler from any folder.

Run NPM from PyCharm using the Node.js and NPM page of the Settings dialog box.

Open the Settings / Preferences Dialog by pressing Ctrl+Alt+S or by choosing File | Settings for Windows and Linux or PyCharm | Preferences for macOS, and click Node.js and NPM under Languages & Frameworks.

On the Node.js and NPM page that opens, the Packages area shows all the Node.js-dependent packages that are currently installed on your computer, both at the global and at the project level. Click .

In the Available Packages dialog box that opens, select the required package to install.

Select the Options check box and type -g in the text box next to it.

Optionally specify the product version and click Install Package to start installation.

Installing the Stylus compiler in a project

Local installation in a specific project restricts the use of a compiler to this project.

Run NPM from PyCharm using the Node.js and NPM page of the Settings dialog box.

Open the Settings / Preferences Dialog by pressing Ctrl+Alt+S or by choosing File | Settings for Windows and Linux or PyCharm | Preferences for macOS, and click Node.js and NPM under Languages & Frameworks.

On the Node.js and NPM page that opens, the Packages area shows all the Node.js-dependent packages that are currently installed on your computer, both at the global and at the project level. Click .

In the Available Packages dialog box that opens, select the required package.

Optionally specify the product version and click Install Package to start installation.

Project level installation is helpful and reliable in template-based projects of the type Node Boilerplate or Node.js Express, which already have the node_modules folder. The latter is important because NPM installs the Stylus compiler in a node_modules folder. If your project already contains such folder, the Stylus compiler is installed there.

Projects of other types or empty projects may not have a node_modules folder. In this case npm goes upwards in the folder tree and installs the Stylus compiler in the first detected node_modules folder. Keep in mind that this detected node_modules folder may be outside your current project root.

Finally, if no node_modules folder is detected in the folder tree either, the folder is created right under the current project root and the Stylus compiler is installed there.

In either case, make sure that the parent folder of the Stylus compiler is added to the PATH variable. This enables you to launch the compiler from any folder.

Creating a file watcher

PyCharm provides a common procedure and user interface for creating File Watchers of all types. The only difference is in the predefined templates you choose in each case.

Make sure the File Watchers plugin is enabled. The plugin is bundled with PyCharm and activated by default. If it is not, enable the plugin. See Enabling and Disabling Plugins for details.

To start creating a File Watcher, open the Settings/Preferences dialog box by choosing File | Settings for Windows and Linux or PyCharm | Preferences for macOS on the main menu, and then click File Watchers under the Tools node. The File Watchers page that opens, shows the list of File Watchers that are already configured in the project.

Click the Add button or press Alt+Insert and choose the Stylus predefined template from the pop-up list.

In the Program text box, specify the path to the executable file:

stylus for macOS and Unix.

stylus.bat for Windows.

Type the path manually or click the Browse button and choose the file location in the dialog box that opens.

Compiling the code

When you open a Stylus file, PyCharm checks whether an applicable file watcher is available in the current project. If such file watcher is configured but disabled, PyCharm displays a pop-up window that informs you about the configured file watcher and suggests to enable it.

If an applicable file watcher is configured and enabled in the current project, PyCharm starts it automatically upon the event specified in the New Watcher dialog.

If the Immediate file synchronization check box is selected, the File Watcher is invoked as soon as any changes are made to the source code.

If the Immediate file synchronization check box is cleared, the File Watcher is started upon save (File | Save All, Ctrl+S) or when you move focus from PyCharm (upon frame deactivation).

PyCharm creates a separate file with the generated output. The file has the name of the source Stylus file and the extension css. The location of the generated files is defined in the Output paths to refresh text box of the New Watcher dialog. However, in the Project Tree, they are shown under the source file which is now displayed as a node.